JP2512931Y2 - Preload device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a preload device used in a webbing retractor for tightly mounting a webbing to an occupant when the vehicle suddenly decelerates.

[Prior art]

The seat belt device is designed to restrain the occupant by the webbing when the vehicle rapidly decelerates. However, if the gap between the webbing and the occupant is large, the restraint performance cannot be sufficiently exhibited. For this reason, there are a preload device that brings the webbing into close contact with an occupant by forcibly pulling the webbing in the winding direction when the vehicle suddenly decelerates, and a webbing winding device including the preload device.

This type of preload device (webbing take-up device) is provided with a clutch mechanism composed of a rotary drum corresponding to the take-up shaft, so that the pre-load device does not normally prevent the take-up shaft from rotating during normal operation. The webbing can be freely taken up and taken out, and the preload device can rapidly rotate the take-up shaft in the take-up direction at the time of sudden deceleration of the vehicle to take up the webbing immediately.

By the way, in the conventional webbing retractor equipped with such a preload device, although the preload device operates during sudden vehicle deceleration and the webbing can be brought into close contact with the occupant by forcibly pulling the webbing in the retracting direction, If a large webbing pull-out force is applied after the webbing is once wound (after the preload device is operated), there is a drawback that the so-called tightening of the webbing still pulls out the webbing as in the conventional webbing retractor.

[Problems to be solved by the device]

In consideration of the above facts, the present invention not only makes the webbing closely contact with the occupant by forcibly pulling the webbing in the winding direction at the time of sudden deceleration of the vehicle, but also prevents the subsequent tightening of the webbing to ensure the occupant. The aim is to obtain a restraint preload device.

[Means for solving the problem]

The preload device according to the present invention is used in a webbing retractor, and is a preload device for forcibly winding an occupant restraining webbing around a take-up shaft. A rotary drum that is integral with the take-up shaft and transmits a rotational force, and a rotary drum that is rotatable in a direction that engages with and separates from the webbing corresponding to the webbing pulled out from the take-up shaft. A clamp member that holds the webbing pulled out from the shaft to prevent the webbing from being pulled out, an urging member that constantly urges the clamp member in the webbing holding direction, and usually the above-mentioned member against the urging force of the urging member. Holding means for holding the clamp member in a state of being separated from the webbing, and forcibly engaging the rotating drum with the winding shaft by being wound around the rotating drum and being tensioned. And a wire for rotating the rotary drum in the webbing take-up direction and releasing the holding of the holding means to allow the clamp member to move in the webbing holding direction, and the wire for webbing during rapid deceleration of the vehicle. And an actuation source for forcibly pulling and tensioning in the winding direction.

[Action]

In the preload device having the above structure, the rotating drum is separated from the winding shaft in a normal state of the vehicle, and the winding shaft is rotatable. Therefore, the occupant restraining webbing can be freely wound up and pulled out.

When the vehicle suddenly decelerates, the actuation source is activated and the wire is pulled and tensioned. As a result, the rotary drum is forcibly engaged with the take-up shaft to be integrated, the take-up shaft is rotated in the webbing take-up direction integrally with the rotary drum, and the webbing is forcibly pulled in the take-up direction. Close contact with the occupants.

At the same time, the holding of the clamp member by the holding means is released by the tension of the wire. Therefore, the clamp member is moved in the webbing clamping direction by the biasing force of the biasing member to clamp the webbing. Therefore, the webbing is prevented from being pulled out from the winding shaft.
Therefore, the subsequent tightening of the webbing is prevented, and the occupant can be reliably restrained.

〔Example〕

1 and 2 show a preload device 10 according to a first embodiment of the present invention and a webbing retractor to which the same is applied.
Twelve cross-sectional views are shown.

In the webbing take-up device 12, a take-up shaft (not shown) is rotatably supported between a pair of side plates 16 facing each other on the frame 14, and the take-up shaft has a webbing 18 for restraining an occupant.
Has one end locked and is wound in layers.

One end of the winding shaft is projected outside the side plate 16 by a predetermined length,
The engagement shaft 20 is integrally connected. Therefore, the engagement shaft 20
Always rotates with the winding shaft. A claw 22 is formed on the outer periphery of the engagement shaft 20 so as to project along the axis. A mainspring (not shown) is connected to the engagement shaft 20, whereby the engagement shaft 20, that is, the winding shaft is always urged in the webbing winding direction (arrow R direction in FIG. 1). Therefore, the winding shaft (engaging shaft 20) is resisted against the biasing force of the mainspring.
The webbing 24 can be pulled out by rotating the webbing in the pulling-out direction (the direction of arrow L in FIG. 1).

A rotary drum 30 is arranged radially outward of the engagement shaft 20. The rotary drum 30 is formed in a substantially cylindrical shape having an inner diameter slightly larger than the outer diameter of the engagement shaft 20, and an inner peripheral surface of the engagement shaft 20.
The engagement shaft 20 can freely rotate without contacting the claw 22 of the. The rotary drum 30 is made of a flexible member, and a part of the outer periphery thereof is cut out in the axial direction so that it is easily deformed. Further, a pair of arms 32 extending outward in the radial direction is formed at the axial end of the rotary drum 30, and is fitted into the fitting hole 42 of the plate 40. Therefore, the rotary drum 30 can integrally rotate the plate 40.

The plate 40 is held on the side plate 16 by the shear pin 46, and thereby the rotary drum 30 is also held at a predetermined position. The shear pin 46 is designed to be sheared when a predetermined shearing force is applied.

The intermediate portion of the wire 48 is wound around the rotary drum 30 in the webbing winding direction (the arrow R direction in FIG. 1). The other end of the wire 48 is connected to the piston of the cylinder 52 as the operation source. A gas generator is attached to the cylinder 52, and a large amount of gas is generated and ejected into the cylinder 52 when an acceleration detection sensor (not shown) detects a rapid vehicle deceleration state. Therefore, in this case, the wire 48 is pulled by the pressure of the ejected gas, the intermediate portion of the wire 48 wound around the rotating drum 30 is tightened, and the rotating drum 30 and the plate 40 are rotated in the webbing winding direction. Power is generated.

Here, the deforming force of the rotating drum 30 is smaller than the shearing force of the shear pin 46, and when the intermediate portion of the wire 48 is wound tightly, the rotating drum 30 is first crushed by the tightening force and the axial line. It is designed to deform toward.

On the other hand, the other end of the wire 48 is engaged with a lock lever 60 as a clamp member arranged immediately above the rotary drum 30.

A support pin 62 is projectingly provided at one end of the lock lever 60 and is swingably supported by the side plate 16. A clamp block 64 having a substantially semicircular cross section is attached to the other end of the lock lever 60 by a support pin 66.

The clamp block 64 faces the intermediate portion in the longitudinal direction of the webbing 18 pulled out from the take-up shaft.
The surface opposed to and is formed in a wavy shape. In addition, a lock base 68 is provided on the frame 14 facing the clamp block 64.
Has been fixed. Webbing 18 on this Rock Base 68
The surface facing the (clamp block 64) is also formed in a wavy shape corresponding to the clamp block 64. For this reason,
By swinging the lock lever 60 around the support pin 62, the webbing 18 can be held between the clamp block 64 and the lock base 68.

A torsion coil spring 70 as an urging member is externally mounted on the support pin 62 of the lock lever 60, and one end of the torsion coil spring 70 is locked to the reinforcing member 17 of the side plate 16 and the other end. The part is locked to the support pin 66. Therefore, the lock lever 60 is always urged in the direction in which the clamp block 64 approaches the lock base 68, that is, the direction in which the webbing 18 is clamped.

An arm 72 forming a holding means extends in the direction of the rotary drum 30 near the support pin 62 of the lock lever 60. The tip portion 48A of the wire 48 described above is clamped and held between the arm 72 and the holding portion 19 which projects from the side plate 16 and constitutes a holding means. That is, in other words, the tip portion 48A of the wire 48 is interposed between the arm 72 and the holding portion 19, so that the clamp block 64 of the lock lever 60 resists the biasing force of the torsion coil spring 70 and the lock base 68. Is held in a state of being separated from the
When the holding of the tip 48 (tip 48A) is released (the tip 48A of the wire 48 is not present between the arm 72 and the holder 19), the clamp block 64 is pressed by the urging force of the torsion coil spring 70. Is configured to move in a direction in which the webbing 18 is clamped.

The webbing retractor 12 having the above-described structure is provided with a lock mechanism (not shown) that is actuated by the acceleration sensor to instantaneously block the rotation of the take-up shaft in the webbing pull-out direction.

 Next, the operation of this embodiment will be described.

In the normal state of the vehicle, the inner peripheral surface of the rotating drum 30 has the engaging shaft 20.
Since the engaging shaft 20 is separated from the claw 22, the engaging shaft 20, that is, the winding shaft can freely rotate in either the winding direction or the drawing direction of the webbing 18. Therefore, the webbing 18 can be freely taken up from the take-up shaft and pulled out in accordance with the change in the posture of the occupant, so that the occupant is not restrained.

When the vehicle reaches a rapid deceleration state (a state in which a large acceleration of about 10 G acts, for example), the acceleration sensor detects this and the gas generator of the cylinder 52 is activated. As a result, the wire 48 is pulled, and the intermediate portion of the wire 48 is tightly wound around the rotating drum 30. Here, since the deformation force of the rotating drum 30 is smaller than the shearing force of the shear pin 46,
First, the rotating drum 30 is crushed by the winding force of the wire 48 and deformed toward the axis. This allows the rotating drum
The inner peripheral surface of 30 bites against the claw 22 of the engaging shaft 20, and the rotating drum 30
And the engaging shaft 20 are integrated (state shown in FIG. 2). Further, a rotating force acts on the plate 40 by the rotation of the rotating drum 30, the shear pin 46 is sheared by this rotating force and the holding is released, and the rotating drum 30 and the engaging shaft 20 are integrated with the plate 40. The webbing is rotated in the winding direction (direction of arrow R in FIG. 2). As a result, the take-up shaft is rapidly rotated in the take-up direction to forcibly take up the webbing 18 and the webbing 18 is tightly attached to the occupant.

At about the same time, the webbing 18 is about to be pulled out from the webbing retractor 12 due to the inertial movement of the occupant, but a locking mechanism (not shown) that momentarily blocks the rotation of the take-up shaft in the webbing pull-out direction is activated. The take-up shaft is prevented from rotating in the webbing pull-out direction. Therefore, the occupant is securely restrained with the webbing 18 tightly attached.

Further, substantially simultaneously with these, as the wire 48 is pulled and the rotary drum 30 is rotated, the tip end 48A of the wire 48 interposed between the arm 72 and the holding portion 19 comes out (the arm 72 and the holding portion 19). (The tip 48A of the wire 48 does not intervene between the wire 48) and the wire 48 and the lock lever 60.
Engagement with the arm 72 (holding the lock lever 60 by the wire 48) is released. Therefore, the lock lever 60 is moved in the webbing clamping direction by the urging force of the torsion coil spring 70 to clamp the webbing 18 (state shown in FIG. 2). Therefore, the webbing 18 is prevented from being pulled out. Therefore, the subsequent tightening of the webbing 18 is prevented, and the occupant can be reliably restrained.

Thus, not only can the webbing 18 be brought into close contact with the occupant by forcibly pulling the webbing 18 in the winding direction during sudden deceleration of the vehicle, but also the subsequent tightening of the webbing 18 can be prevented and the occupant can be reliably restrained. .

Next, another embodiment of the present invention will be described. The same reference numerals as in the first embodiment denote the same parts as those in the first embodiment, and a description thereof will be omitted.

3 and 4, a preload device 80 according to a second embodiment of the present invention and a webbing retractor to which the same is applied.
A cross-sectional view of 82 is shown.

In the webbing retractor 82, the tip of the wire 48 is a piece.
It is fixed to the plate 40 by 50. Further, the arm 72 of the lock lever 60 has a shear pin that constitutes a holding means.
84 is fixed, and further, the intermediate portion of the wire 48 which is being wound around the rotating drum 30 is further wound.

Here, normally, the lock lever 60 is twisted by the wire 48 wound around the shear pin 84 to the coil spring 70.
It is held against the urging force of the clamp block 64
Is separated from the lock base 68. on the other hand,
When the shear pin 84 is sheared, the lock lever 60 is released from the holding state, and the clamp block 64 moves in the direction in which the webbing 18 is clamped by the biasing force of the torsion coil spring 70.

In this webbing retractor 82 as well, when the vehicle is in a sudden deceleration state, the rotary drum 30 is integrated with the engaging shaft 20 and rotated in the webbing retracting direction. As a result, the webbing 18 is forcibly wound up, and the webbing 18 is tightly attached to the occupant.

At approximately the same time, when the wire 48 is pulled and tensioned, the shear pin 84 of the arm 72 is sheared. For this reason,
The lock lever 60 is released, and the lock lever 60 is moved in the webbing clamping direction by the urging force of the torsion coil spring 70 to clamp the webbing 18 (state shown in FIG. 4). Therefore, the withdrawal of the webbing 18 is prevented, the subsequent tightening of the webbing 18 is prevented, and the occupant can be reliably restrained.

As described above, also in the webbing retractor 82, not only is the webbing 18 brought into close contact with the occupant by forcibly pulling the webbing 18 in the retracting direction at the time of sudden deceleration of the vehicle,
Further tightening of the webbing 18 is prevented, and the occupant can be reliably restrained.

5 and 6 show a preload device 90 according to a third embodiment of the present invention and a webbing retractor to which the same is applied.
A cross-section of 92 is shown.

In the webbing retractor 92, a cam 94 as a holding means is arranged between the rock lever 60 and the rotary drum 30. The cam 94 has one end rotatably supported by a support shaft 95. A holding hole 96 having a substantially L-shape is formed near the other end of the cam 94, and a pin 98 fixed to the lock lever 60 is movably fitted therein.

Further, an arm portion 99 is formed so as to project in the middle portion of the cam 94. An intermediate portion of the wire 48 (between the rotary drum 30 and the cylinder 52) after being wound around the rotary drum 30 is in contact with the arm portion 99 in a relaxed state.

Here, the pin 98 is normally located at one end of the holding hole 96, which causes the cam 94 to rotate in the torsion coil spring 70.
The lock lever 60 is held against the urging force of the clamp block 64 so that the clamp block 64 is separated from the lock base 68. On the other hand, when the wire 48 is tensioned, the arm portion 99 is pressed by the wire 48, whereby the cam 94 rotates around the support shaft 95, and the pin 98 moves to the other end side in the holding hole 96, whereby the cam The holding of the lock lever 60 by 94 is released, and the clamp block 64 is moved in the direction of holding the webbing 18 by the urging force of the torsion coil spring 70.

In this webbing retractor 92 as well, when the vehicle rapidly decelerates, the rotary drum 30 is integrated with the engaging shaft 20 and rotated in the webbing retracting direction. As a result, the webbing 18 is forcibly wound up, and the webbing 18 is tightly attached to the occupant.

Further, at substantially the same time, when the wire 48 is pulled and tensioned, the wire 48 presses the arm portion 99 to rotate the cam 94 and move the pin 98 to the other end side of the holding hole 96, whereby the lock lever 60 by the cam 94 is moved. Is released. Therefore, the lock lever 60 is moved in the webbing holding direction by the biasing force of the torsion coil spring 70, and holds the webbing 18 (state shown in FIG. 6). Therefore, the withdrawal of the webbing 18 is prevented, the subsequent tightening of the webbing 18 is prevented, and the occupant can be reliably restrained.

As described above, also in the webbing retractor 92, not only is the webbing 18 brought into close contact with the occupant by forcibly pulling the webbing 18 in the retracting direction at the time of sudden deceleration of the vehicle,
Further tightening of the webbing 18 is prevented, and the occupant can be reliably restrained.

[Effect of device]

As described above, the preload device according to the present invention not only makes the webbing closely contact the occupant by forcibly pulling the webbing in the winding direction at the time of sudden deceleration of the vehicle,
It also has an excellent effect of reliably restraining the occupant by preventing the subsequent tightening of the webbing.

[Brief description of drawings]

1 and 2 are sectional views of a preload device according to a first embodiment of the present invention and a webbing retractor to which the preload device is applied, and FIGS. 3 and 4 are preload devices according to a second embodiment of the present invention. FIG. 5 is a sectional view of an apparatus and a webbing retractor to which the apparatus is applied, and FIGS. 5 and 6 are sectional views of a preload apparatus and a webbing retractor to which the preload apparatus is applied according to a third embodiment of the present invention. 10 …… Preload device, 12 …… Webbing retractor, 18
...... Webbing, 19 …… Holding part (holding means), 20 …… Engagement shaft, 30 …… Rotary drum, 48 …… Wire, 52 …… Cylinder (operating source), 60 …… Rock lever (clamping member),
64 ... Clamp block (clamp member), 68 ... Rock base, 70 ... Torsion coil spring (biasing member), 72 ... Arm (holding means), 80 ... Preload device, 82 ... Webbing take-up Device, 84 ... Sheer pin (holding device), 90 ... Preload device, 92 ... Webbing retractor, 94 ... Cam (holding device).

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-3-25053 (JP, A) JP-A 64-41442 (JP, A) JP-A 2-262448 (JP, A) Actual development Sho-63- 74358 (JP, U) Special Table 1-502735 (JP, A)

Claims (1)

(57) [Scope of utility model registration request] 1. A preload device for use in a webbing retractor for forcibly winding an occupant restraining webb on a take-up shaft, wherein the pre-load device is arranged so as to be engageable with the take-up shaft, and when engaged, A rotary drum that integrally transmits a rotational force, and a rotary drum that is rotatably disposed in a direction that engages with and separates from the webbing in correspondence with the webbing pulled out from the winding shaft,
In the engaged state, a clamp member that holds the webbing pulled out from the take-up shaft to prevent the webbing from being pulled out, an urging member that constantly urges the clamp member in the webbing holding direction, and normally an urging member is urged. Holding means for holding the clamp member in a state of being separated from the webbing against the force, and the rotating drum is forcibly engaged with the winding shaft by being tensioned by being wound around the rotating drum to be integrated. A wire for rotating the rotary drum in the webbing winding direction and releasing the holding of the holding means to allow the clamp member to move in the webbing holding direction, and a wire forcing the wire in the webbing winding direction when the vehicle suddenly decelerates. A preloading device comprising: